None.
Not Applicable.
1. Field of the Invention
This invention relates generally to a bale binding machine utilizing controlled pins and, more particularly, a bale binding machine that utilizes controlled pins to guide the path of a wire (or strap) around a bale such that strength-reducing bending is not introduced to the wire. The bale binding machine binds bales of fibrous bulk materials such as cotton and nylon.
2. Related Art
Fibrous bulk materials include cotton and nylon. Fibrous bulk materials are commonly formed into bales by compression and binding. There is a continuing need in the art to improve this bale binding process by improving efficiency, reliability and accuracy. There are various constraints on improvements to the bale binding process including: (1) the nature of the fibrous material; (2) the compressive force or loading; and (3) the loading of the fibrous material into a bale compression box ; (3) wrapping baling wire around the bale.
These constraints interact to create control challenges. For example, the compressive force required to compress bulk fibrous material to a certain physical volume fluctuates. Specifically, variations in heat and humidity cause the fibrous material to expand or contract, with an expanded material volume requiring more compressive force to compress the material to a particular volume, and a contracted material volume requiring less force for compression. In addition, when a compressed, originally-contracted material is later exposed to heat and humidity, the material attempts to expand, imposing additional stresses on the baling wire.
Due to the very nature of any bulk material, when the material is loaded into the compression box prior to compression, the bulk material can become unevenly distributed within the compression box. When the compressing ram compresses the unevenly distributed bulk material, some portions of material experience greater compression than other portions. After the baling wires are applied and secured around the bale, the compression on the bale is released and the fibrous bulk material of the bale expands in volume. Because the distribution of material in the bale is uneven, a varying amount of tension is experience by the baling straps or baling wires. An excessive amount of tension in baling straps or baling wire applied through the expansion of bulk material can cause the baling strap or wire to fail. Alternatively, the baling wire has the potential to elongate have the length altered in some way.
Baling wire or baling strap performance requirements vary depending on the bulk material at issue. Such requirements range from general operational parameters to industry to standard specifications. The Cotton Council has a baling constraint wherein the length of the wire (or strap) around the bale must fall within a particular range and the tension that the wire (or strap) must withstand has a particular range.
U.S. Wire Tie, a company based in Carthage, Mo., has an existing system, the 340 Series, for baling bulk materials. This system uses a hydraulic twist knot wire tying system to bind bales. In such systems, 8 gauge wire is utilized as the baling wire. However, hydraulic systems are slowly becoming less desirable because any leak of hydraulic fluid onto the bulk material ruins the material and requires that the baling equipment be cleaned prior to restarting the baling operation. To avoid the ruination of bulk material and prevent the loss of operational time and avoid the accompanying cleaning costs, this, there is a need in the art to provide a power source for a baling machine that does not use hydraulic fluid.
As the inventors have explored the feasibility of electric systems, it has been discovered that such systems require electrically-powered, knot-tying heads that are substantially larger than hydraulic knot-tying heads. This larger dimension, however, results in an inability to feed the wire around the bale with enough clearance from the bale to permit tying and still fall within the required length and strength specifications of the Cotton Council. Alternatively, it has been discovered that the baling wire must be sharply bent to achieve the length specification of the Cotton Council. However, any sharp bend in the wire decreases the ability of the wire to withstand the expansion forces of a cotton bale that has been released from compressive force.
In addition, as bulk material such as cotton or nylon is a commodity item, production costs are always examined to determine where such costs may be lowered. One heretofore fixed cost is the baling wire or strap. Costs for baling wire or baling strap are generally based on volume. Accordingly there are no options for lowering such cost without increasing purchasing volume. However, if the gauge of the wire can be increased without sacrificing strength, the smaller diameter wire (or strap) will be cheaper, thus reducing overall production cost.
Accordingly, there is a need in the art to provide an electrically powered baling system that can meet the requirements of the Cotton Council.
There is also need in the art to provide a baling system that utilizes a smaller gauge of wire for baling bulk material.
It is in view of the above problems that the present invention was developed. The invention controls stresses applied to a baling wire by employing pull pins. The wire is directed around the pull pins to moderate bending in the baling wire. This is because the pull pins are disposed between a wire track and a wire tying head. Without the pull pins, the baling wire would circle around the wire track and bend sharply to (and travel linearly to) the tying head. With the pull pins, the wire assumes an arcuate shape between the wire track and the tying head. It is critical to the invention that the pull pins are longitudinally movable, with the use of a solenoid. The pull pins are extended to guide the baling wire, and are retracted to avoid interference when the bale is released from a compression box and meets the wire.
Because the pins reduce wire stress, while avoiding interference when the bale is released, the present invention permits a reduction in wire size to 10 gauge wire. While less expensive, 10 gauge wire was, until the present invention, considered incapable of reliably binding bales of cotton.